Question

A sample of concrete is prepared by using $500g$ of cement with water cement ratio of $0.55$ and $240N/m{m}^2$ intrinsic strength of gel. The theoretical strength of concrete on full hydration will be nearly.

• A. $148N/m{m}^2$
• B. $126N/m{m}^2$
• C. $104N/m{m}^2$
• D. $82N/m{m}^2$

Answer 1

The correct option is C $104N/m{m}^2$

Intrinsic strength of gel $=240N/m{m}^2$
Weight of cement $=500gm$
$\frac{W}{C}=0.55$
Weight of water $=500\times 0.55=275gm$
Volume of water $=275ml$ $(\therefore {\rho }_{\text{water}}=1gm/cc)$
Gel space ratio $=\frac{0.657C}{0.319C+W}=\frac{0.657\times 500}{0.319\times 500+275}$
$=0.756$
Theoretical strength of concrete $=240\times (0.756{)}^3$
$=103.71N/m{m}^2$